Forecast Surplus Baseload Generation Report

Surplus Baseload Generation (SBG) is a condition that occurs when electricity production from baseload facilities is greater than Ontario demand. There are limited options available to lower output from baseload generators in order to maintain the balance between supply and demand. It is expected that incidences of SBG may increase as Ontario's supply mix continues to change. Current economic conditions have increased the frequency of SBG as overall electricity demand has declined. The reports below indicate the hours in each day where an SBG condition is forecast to occur. The purpose of the report is to enable Market Participants to make decisions about scheduling their resources.

Forecast Surplus Baseload Generation Reports
Mon	Tues	Wed	Thurs	Fri
				Feb 26
Mar 1	Mar 2	Mar 3	Mar 4	Mar 5
Mar 8	Mar 9	Mar 10	Mar 11	Mar 12

Note: The SBG Report is now presented in XML (eXtensible Mark-up Language) format which can be viewed using a browser.

Market participants can assist in managing the appropriate balance of supply when there is surplus baseload generation through the following actions:

• avoiding off-peak hours when scheduling commissioning generation
• scheduling generation with minimum run times to avoid operation during off-peak hours
• ensuring schedules for variable and self-scheduling generators are accurate and up to date and offers prices reflect the price at which these units do not wish to operate (for example, some generators may not wish to operate if prices are negative)
• increasing consumption in low price periods or de-synchronizing generators from the IESO-Controlled Grid or those embedded in distribution systems will also assist in managing this matter

SBG periods are typically the result of low demand and can be exacerbated by:

• Spring freshet (snow melt), when hydroelectric stations cannot lower generation output
• Periods when most generators are available, having completed outages in preparation for the peak periods in summer and winter
• High production from variable resources such as wind generation.

Often these events can be foreseen in the planning timeframe. In real-time, SBG can often be addressed by exports. However, sometimes events such as unexpectedly high production of variable resources (i.e. under-forecasting from participants) or low export levels to adjacent areas can lead to surplus generation conditions in real-time.

Calculation:

• SBG is calculated by subtracting the forecasted Ontario demand from the forecasted baseload energy. Exports are excluded from the calculation.
• Baseload energy is the sum of all available nuclear, must-run hydroelectric, self-scheduling, commissioning and intermittent generators.
• Only positive values of SBG are displayed to simplify the report.
  
  

Publication:

• The SBG report will be published every weekday, excluding holidays, by 17:00 (EST).
• The data for the first ten days of the report are updated daily using forecasted weather.
• The remaining data will be updated every Thursday using average historical weather.  If Thursday is a statutory holiday then the update will take place on the next business day.